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Franco VG, Rodríguez SJ, Calaza FC, Passeggi MCG, Ruano GD. Novel mixed self-assembled monolayers of L-cysteine and methanol on gold surfaces under ambient conditions. NANOSCALE 2024; 16:15366-15380. [PMID: 39091174 DOI: 10.1039/d4nr01848f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
In this work, we carried out an experimental and theoretical study on the formation of self-assembled monolayers of L-cysteine molecules on gold surfaces in the presence of methanol as a solvent. We report for the first time L-cysteine and methanol ordered structures forming a mixed self-assembled mono-layer on Au(100) surfaces under ambient conditions. Finger-like ordered structures with a relative height of 0.10-0.20 nm, average width of 2.0 nm and variable lengths were observed using scanning tunneling microscopy under room temperature and ambient pressure conditions. Using X-ray photoemission spectroscopy, it was determined that L-cysteine molecules bind to the gold surface through the sulfur atom of their thiol group in two molecular configurations: neutral and zwitterionic. We found that the finger-like structures are the result of complex interactions of L-cysteine molecules with gold surfaces and L-cysteine molecules with methanol molecules and among all three components of the system (L-cysteine + methanol + gold surfaces). These interactions were detected through attenuated total reflectance-Fourier transform infrared spectroscopy. Furthermore, adsorbate/substrate interactions were studied by employing ab initio calculations using density functional theory, resulting in molecular arrangements formed by chains of L-cysteine pairs surrounded by physisorbed methanol molecules.
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Affiliation(s)
- Vanina Gisela Franco
- Instituto de Física del Litoral (IFIS Litoral), Consejo Nacional de Investigaciones Científicas y Técnicas and Universidad Nacional del Litoral (CONICET-UNL), Güemes 3450, (3000) Santa Fe, Argentina.
- Facultad de Ingeniería Química (FIQ), Universidad Nacional del Litoral (UNL), Santiago del Estero 2829, (3000) Santa Fe, Argentina
| | - Sindy Julieth Rodríguez
- Instituto de Física del Litoral (IFIS Litoral), Consejo Nacional de Investigaciones Científicas y Técnicas and Universidad Nacional del Litoral (CONICET-UNL), Güemes 3450, (3000) Santa Fe, Argentina.
| | - Florencia Carolina Calaza
- Facultad de Ingeniería Química (FIQ), Universidad Nacional del Litoral (UNL), Santiago del Estero 2829, (3000) Santa Fe, Argentina
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC), Consejo Nacional de Investigaciones Científicas y Técnicas and Universidad Nacional del Litoral (CONICET-UNL), Güemes 3450, (3000) Santa Fe, Argentina
| | - Mario César Guillermo Passeggi
- Instituto de Física del Litoral (IFIS Litoral), Consejo Nacional de Investigaciones Científicas y Técnicas and Universidad Nacional del Litoral (CONICET-UNL), Güemes 3450, (3000) Santa Fe, Argentina.
- Facultad de Ingeniería Química (FIQ), Universidad Nacional del Litoral (UNL), Santiago del Estero 2829, (3000) Santa Fe, Argentina
| | - Gustavo Daniel Ruano
- Centro Atómico Bariloche (CAB), Comisión Nacional de Energía Atómica (CNEA), Av. Exequiel Bustillo 9500, (8400) San Carlos de Bariloche, Argentina
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2
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Satta M, Zema N, Turchini S, Franchi S, Contini G, Ciavardini A, Grazioli C, Coreno M, de Simone M, Tomellini M, Piccirillo S. Adsorption and Dissociation of R-Methyl p-Tolyl Sulfoxide on Au(111). ACS OMEGA 2023; 8:16471-16478. [PMID: 37179596 PMCID: PMC10173319 DOI: 10.1021/acsomega.3c01647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/29/2023] [Indexed: 05/15/2023]
Abstract
Sulfur-based molecules producing self-assembled monolayers on gold surfaces have long since become relevant functional molecular materials with many applications in biosensing, electronics, and nanotechnology. Among the various sulfur-containing molecules, the possibility to anchor a chiral sulfoxide to a metal surface has been scarcely investigated, despite this class of molecules being of great importance as ligands and catalysts. In this work, (R)-(+)-methyl p-tolyl sulfoxide was deposited on Au(111) and investigated by means of photoelectron spectroscopy and density functional theory calculations. The interaction with Au(111) leads to a partial dissociation of the adsorbate due to S-CH3 bond cleavage. The observed kinetics support the hypotheses that (R)-(+)-methyl p-tolyl sulfoxide adsorbs on Au(111) in two different adsorption arrangements endowed with different adsorption and reaction activation energies. The kinetic parameters related to the adsorption/desorption and reaction of the molecule on the Au(111) surface have been estimated.
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Affiliation(s)
- Mauro Satta
- Istituto
per lo studio dei Materiali Nanostrutturati-CNR (ISMN-CNR), Department
of Chemistry, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Nicola Zema
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
| | - Stefano Turchini
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
| | - Stefano Franchi
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
| | - Giorgio Contini
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- Dipartimento
di Fisica, Università di Roma “Tor
Vergata”, Via
della Ricerca Scientifica, 00133 Rome, Italy
| | - Alessandra Ciavardini
- University
of Nova Gorica, SI-5001 Nova Gorica, Slovenia
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Basovizza Area Science Park, 34149 Trieste, Italy
| | - Cesare Grazioli
- Istituto
Officina dei Materiali-CNR (IOM-CNR), Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Marcello Coreno
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Basovizza Area Science Park, 34149 Trieste, Italy
| | - Monica de Simone
- Istituto
Officina dei Materiali-CNR (IOM-CNR), Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Massimo Tomellini
- Dipartimento
di Scienze e Tecnologie Chimiche, Università
di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Susanna Piccirillo
- Istituto
di Struttura della Materia-CNR (ISM-CNR), Via Fosso del Cavaliere 100, 00133 Rome, Italy
- Dipartimento
di Scienze e Tecnologie Chimiche, Università
di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Rome, Italy
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3
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Menachekanian S, Voegtle MJ, Warburton RE, Hammes-Schiffer S, Dawlaty JM. Inductive Effect Alone Cannot Explain Lewis Adduct Formation and Dissociation at Electrode Interfaces. J Am Chem Soc 2023; 145:5759-5768. [PMID: 36862607 DOI: 10.1021/jacs.2c12370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Understanding breaking and formation of Lewis bonds at an electrified interface is relevant to a large range of phenomena, including electrocatalysis and electroadsorption. The complexities of interfacial environments and associated reactions often impede a systematic understanding of this type of bond at interfaces. To address this challenge, we report the creation of a main group classic Lewis acid-base adduct on an electrode surface and its behavior under varying electrode potentials. The Lewis base is a self-assembled monolayer of mercaptopyridine and the Lewis acid is BF3, forming a Lewis bond between nitrogen and boron. The bond is stable at positive potentials but cleaves at potentials more negative of approximately -0.3 V vs Ag/AgCl without an associated current. We also show that if the Lewis acid BF3 is supplied from a reservoir of Li+BF4- electrolyte, the cleavage is completely reversible. We propose that the N-B Lewis bond is affected both by the field-induced intramolecular polarization (electroinduction) and by the ionic structures and ionic equilibria near the electrode. Our results indicate that the second effect is responsible for the Lewis bond cleavage at negative potentials. This work is relevant to understanding the fundamentals of electrocatalytic and electroadsorption processes.
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Affiliation(s)
- Sevan Menachekanian
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Matthew J Voegtle
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | | | | | - Jahan M Dawlaty
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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4
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Steen JD, Volker A, Duijnstee DR, Sardjan AS, Browne WR. pH-Induced Changes in the SERS Spectrum of Thiophenol at Gold Electrodes during Cyclic Voltammetry. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:7680-7687. [PMID: 35558822 PMCID: PMC9082592 DOI: 10.1021/acs.jpcc.2c00416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/23/2022] [Indexed: 06/15/2023]
Abstract
Thiophenol is a model compound used in the study of self-assembly of arylthiols on gold surfaces. In particular, changes in the surface-enhanced Raman scattering (SERS) spectra of these self-assembled monolayers (SAMs) with a change of conditions have been ascribed to, for example, differences in orientation with respect to the surface, protonation state, and electrode potential. Here, we show that potential-induced changes in the SERS spectra of SAMs of thiophenol on electrochemically roughened gold surfaces can be due to local pH changes at the electrode. The changes observed during the potential step and cyclic voltammetry experiments are identical to those induced by acid-base switching experiments in a protic solvent. The data indicate that the potential-dependent spectral changes, assigned earlier to changes in molecular orientation with respect to the surface, can be ascribed to changes in the pH locally at the electrode. The pH at the electrode can change as much as several pH units during electrochemical measurements that reach positive potentials where oxidation of adventitious water can occur. Furthermore, once perturbed by applying positive potentials, the pH at the electrode takes considerable time to recover to that of the bulk solution. It is noted that the changes in pH even during cyclic voltammetry in organic solvents can be equivalent to the addition of strong acids, such as CF3SO3H, and such effects should be considered in the study of the redox chemistry of pH-sensitive redox systems and potential-dependent SERS in particular.
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Affiliation(s)
- Jorn D. Steen
- Molecular Inorganic Chemistry, Stratingh
Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, Groningen 9747AG, Netherlands
| | - Anouk Volker
- Molecular Inorganic Chemistry, Stratingh
Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, Groningen 9747AG, Netherlands
| | - Daniël R. Duijnstee
- Molecular Inorganic Chemistry, Stratingh
Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, Groningen 9747AG, Netherlands
| | - Andy S. Sardjan
- Molecular Inorganic Chemistry, Stratingh
Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, Groningen 9747AG, Netherlands
| | - Wesley R. Browne
- Molecular Inorganic Chemistry, Stratingh
Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, Groningen 9747AG, Netherlands
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5
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Gurdal Y. Aromatic versus aliphatic thiols on Au(111) surface: a DFT exploration of adsorption registry and electronic structure. MOLECULAR SIMULATION 2019. [DOI: 10.1080/08927022.2019.1663844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Yeliz Gurdal
- Department of Bioengineering, Adana Alparslan Turkes Science and Technology University, Adana, Turkey
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6
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Blowey PJ, Rochford LA, Duncan DA, Warr DA, Lee TL, Woodruff DP, Costantini G. Probing the interplay between geometric and electronic structure in a two-dimensional K-TCNQ charge transfer network. Faraday Discuss 2019; 204:97-110. [PMID: 28792036 DOI: 10.1039/c7fd00093f] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Scanning tunnelling microscopy (STM), low energy electron diffraction (LEED), ultraviolet and soft X-ray photoelectron spectroscopy (UPS and SXPS) have been used to characterise the formation of a coadsorption phase of TCNQ and K on Ag(111), while the normal incident X-ray standing waves (NIXSW) technique has been used to obtain quantitative structural information. STM and LEED show that an ordered incommensurate phase is formed in which the K atoms are surrounded by four TCNQ molecules in a 'windmill' motif, characteristic of other metal/TCNQ phases, in which the nominal TCNQ : K stoichiometry is 1 : 1. UPS and SXPS data indicate the TCNQ is in a negatively-charged state. NIXSW results show that the carbon core of the TCNQ is essentially planar at a height above the Ag(111) surface closely similar to that found without coadsorbed K. In the presence of TCNQ the height of the K ions above the surface is significantly larger than on clean Ag(111), and the ions occupy sites above 'holes' in the TCNQ network. NIXSW data also show that the N atoms in the molecules must occupy sites with at least two different heights above the surface, which can be reconciled by a tilt or twist of the TCNQ molecules, broadly similar to the geometry that occurs in bulk TCNQ/K crystals.
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Affiliation(s)
- P J Blowey
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK.
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7
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Kankate L, Hamann T, Li S, Moskaleva LV, Gölzhäuser A, Turchanin A, Swiderek P. Tracking down the origin of peculiar vibrational spectra of aromatic self-assembled thiolate monolayers. Phys Chem Chem Phys 2018; 20:29918-29930. [PMID: 30475374 DOI: 10.1039/c8cp03651a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Several studies have previously observed surprisingly low frequencies for the C-H stretching modes of self-assembled monolayers (SAMs) prepared from aromatic thiols. The reason for this property has so far remained elusive. Therefore, we report a novel study of the vibrational spectra of SAMs prepared on Au from two different aromatic thiols, namely, 4'-nitro-1,1'-biphenyl-4-thiol (NBPT) and 4-aminothiophenol (ATP). The SAMs were prepared by vapor deposition (VD) in ultrahigh vacuum (UHV) as well as by the solution method (SM) and their quality was controlled by X-ray photoelectron spectroscopy (XPS). In addition, amino terminated SAMs were also obtained by electron irradiation and by chemical reduction of NBPT SAMs. Beside infrared reflection absorption spectroscopy (IRRAS), we have employed high resolution electron energy loss spectroscopy (HREELS), by which VD SAMs can be studied in situ, i.e. without exposing them to air. Hence, we can exclude possible contributions of solvent molecules to the vibrational spectra. Nonetheless, HREELS in fact reveals the same large red shift of the C-H stretching modes in the SAMs as also observed in ex situ IRRAS experiments. In contrast, HREELS for physisorbed ATP and ATP in a KBr pellet measured by transmission infrared spectroscopy exhibit the expected aromatic bands. Using a computational approach, we can exclude molecular packing effects as origin of this shift. Therefore, we propose chemical changes in the aromatic rings during SAM formation as an alternative explanation for the observed frequency shift. As another striking effect, the N-H stretching vibrational modes of the amino-terminated SAMs are extremely weak in both IRRAS and HREELS despite the fact that XPS confirms the presence of amino groups. A very weak signal is observed only in the case of an electron irradiated NBPT SAM. In contrast, an energy loss ascribed to the N-H stretching vibrations is clearly observed in HREELS of ATP physisorbed on an ATP SAM and on graphite as well as in the transmission infrared spectrum of ATP in KBr. The extremely low intensity of these vibrations in the SAM is traced back to the inherently low transition dipole moment for the excitation of N-H stretching modes in free N-H groups. Furthermore, the calculations suggest that the much stronger signals of N-H stretching modes involved in hydrogen-bonding with adjacent amino groups are suppressed because these vibrations are oriented parallel to the surface.
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Affiliation(s)
- Laxman Kankate
- University of Bremen, Faculty 2 (Chemistry/Biology), Institute of Applied and Physical Chemistry, Leobener Straße 5 (NW2), Postfach 330440, 28334 Bremen, Germany.
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8
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Lobo Maza F, Grumelli D, Carro P, Vericat C, Kern K, Salvarezza RC. The role of the crystalline face in the ordering of 6-mercaptopurine self-assembled monolayers on gold. NANOSCALE 2016; 8:17231-17240. [PMID: 27714158 DOI: 10.1039/c6nr06148f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Well-ordered molecular films play an important role in nanotechnology, from device fabrication to surface patterning. Self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) on the Au(100)-(1 × 1) and Au(111)-(1 × 1) have been used to understand the interplay of molecule-substrate interactions for heterocyclic thiols capable of binding to the surface by two anchors, which spontaneously form a highly disordered film on Au(111). Our results reveal that for the same surface coverage the simple change of the substrate from Au(111)-(1 × 1) to Au(100)-(1 × 1) eliminates molecular disorder and yields well-ordered SAMs. We discuss these findings in terms of differences in the surface mobility of 6MP species on these surfaces, the energetics of the adsorption sites, and the number of degrees of freedom of these substrates for a molecule with reduced surface mobility resulting from its two surface anchors. These results reveal the presence of subtle molecule-substrate interactions involving the heteroatom that drastically alter SAM properties and therefore strongly impact on our ability to control physical properties and to build devices at the nanoscale.
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Affiliation(s)
- Flavia Lobo Maza
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata - CONICET- Sucursal 4 Casilla de Correo 16, (1900) La Plata, Argentina.
| | - Doris Grumelli
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata - CONICET- Sucursal 4 Casilla de Correo 16, (1900) La Plata, Argentina.
| | - Pilar Carro
- Área de Química Física, Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, Instituto de Materiales y Nanotecnología, Avda. Francisco Sánchez, s/n 38071-La Laguna, Tenerife, Spain
| | - Carolina Vericat
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata - CONICET- Sucursal 4 Casilla de Correo 16, (1900) La Plata, Argentina.
| | - Klaus Kern
- Max Planck Institute FKF, Stuttgart, Germany and EPFL, Lausanne, Switzerland
| | - Roberto C Salvarezza
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata - CONICET- Sucursal 4 Casilla de Correo 16, (1900) La Plata, Argentina.
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9
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Nouchi R, Tanimoto T. Substituent-Controlled Reversible Switching of Charge Injection Barrier Heights at Metal/Organic Semiconductor Contacts Modified with Disordered Molecular Monolayers. ACS NANO 2015; 9:7429-7439. [PMID: 26161447 DOI: 10.1021/acsnano.5b02473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Electrically stimulated switching of a charge injection barrier at the interface between an organic semiconductor and an electrode modified with a disordered monolayer (DM) is studied by using various benzenethiol derivatives as DM molecules. The switching behavior is induced by a structural change in the DM molecules and is manifested as a reversible inversion of the polarity of DM-modified Au electrode/rubrene/DM-modified Au electrode diodes. The switching direction is found to be dominantly determined by the push-back effect of the thiol bonding group, while the terminal group modulates the switching strength. A device with 1,2-benzenedithiol DMs exhibited the highest switching ratios of 20, 10(2), and 10(3) for the switching voltages of 3, 5, and 7 V, respectively. A variation in the tilt angle of benzenethiol DMs due to the application of 7 V is estimated to be smaller than 23.6° by model calculations. This study offers an understanding for obtaining highly stable operations of organic electronic devices, especially with molecular modification layers.
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Affiliation(s)
- Ryo Nouchi
- Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, Sakai 599-8570, Japan
| | - Takaaki Tanimoto
- Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, Sakai 599-8570, Japan
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Bashir A, Heck A, Narita A, Feng X, Nefedov A, Rohwerder M, Müllen K, Elstner M, Wöll C. Charge carrier mobilities in organic semiconductors: crystal engineering and the importance of molecular contacts. Phys Chem Chem Phys 2015; 17:21988-96. [DOI: 10.1039/c5cp03171k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have conducted a combined experimental and theoretical study on the packing optimization of hexa-peri-hexabenzocoronene (HBC) as organic semiconductor.
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Affiliation(s)
- Asif Bashir
- Max-Planck-Institut für Eisenforschung GmbH
- 40237 Düsseldorf
- Germany
| | - Alexander Heck
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
- HEiKA – Heidelberg Karlsruhe Research Partnership
| | | | - Xinliang Feng
- Max-Planck Institute for Polymer Research
- 55128 Mainz
- Germany
| | - Alexei Nefedov
- Institute of Functional Interfaces
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen
- Germany
| | | | - Klaus Müllen
- Max-Planck Institute for Polymer Research
- 55128 Mainz
- Germany
| | - Marcus Elstner
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
- HEiKA – Heidelberg Karlsruhe Research Partnership
| | - Christof Wöll
- Institute of Functional Interfaces
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen
- Germany
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Forster-Tonigold K, Stammer X, Wöll C, Groß A. Temperature effects in the vibrational spectra of self-assembled monolayers. PHYSICAL REVIEW LETTERS 2013; 111:086102. [PMID: 24010456 DOI: 10.1103/physrevlett.111.086102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Indexed: 06/02/2023]
Abstract
The vibrational spectrum of a thiolate-based self-assembled monolayer fabricated by the adsorption of benzylmercaptan on a Au(111) substrate is studied using a combined experimental and theoretical approach employing infrared reflection absorption spectroscopy and density functional theory. The vibrational spectra are derived both using a finite differences approach and from ab initio molecular dynamics simulations at various temperatures. In addition, the possibility of adsorbate-induced reconstructions of the Au(111) substrate is taken into account. It turns out that the measured spectra can only be understood by taking finite temperatures into account.
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Affiliation(s)
- Katrin Forster-Tonigold
- Helmholtz Institute Ulm (HIU) Electrochemical Energy Storage, D-89069 Ulm, Germany and Institute of Theoretical Chemistry, Ulm University, D-89069 Ulm, Germany
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